This specification relates to advertising and, in particular, optimizing bid prices for online advertising auctions.
Online display advertising delivers promotional messages to consumers by using visual advertisements (or “ads”) in web pages. A publisher of a web page can insert an ad space in the web page. When the web page is displayed in a browser, a visual advertisement (a “creative”) of an advertiser can be dynamically retrieved from an ad server for the advertiser, and displayed in the ad space. The act of displaying or serving a creative on a web page is often referred to as an impression.
An ad inventory is a collection of one or more ad spaces on web pages served by a publisher's web sites. Publisher can sell their ad inventories to advertisers. Multiple publishers and multiple advertisers can participate in auctions in which selling and buying of ad inventories take place. Auctions can be conducted by an ad network or ad exchange that brokers between a group of publishers and a group of advertisers.
Selling and buying ad spaces can be based on pricing or payment models such as cost per thousand impressions (CPM), cost per click (CPC), and cost per action or acquisition (CPA). In the CPM model, advertisers typically pay for every impression of their advertisement, the price paid for each impression is measured in price per 1000 (“mille”) impressions. In the CPC model, advertisers typically pay each time a viewer clicks on their advertisement. In the CPA model, advertisers pay for every action, such as a sale or registration, completed as a result of a viewer clicking on their advertisement.